Struct Config 

pub struct Config {

    pub addr: String,
    pub token: String,
    pub db_path: String,
    pub git_commit: String,
    pub backup_dir: String,
    pub backup_interval: Duration,
    pub backup_keep: usize,
    pub rate_limit_window: Duration,
    pub rate_limit_max: u32,
    pub trusted_ip_header: String,
    pub merge_enabled: bool,
    pub merge_timeout: Duration,
    pub claude_bin: String,
    pub claude_status_interval: Duration,
    pub ephemeral_device_ttl: Duration,
    pub public_url: String,
    pub tls: TlsMode,
    pub tls_max_connections: usize,
}

What recall-server needs.

Every field has a default that is safe to run with, except token, which has none — see ConfigError::MissingToken.

Field	Variable	Default
addr	RECALL_HOST, RECALL_PORT	0.0.0.0:8787
token	RECALL_TOKEN	required
db_path	RECALL_DB_PATH	data/recall.db
git_commit	RECALL_GIT_COMMIT	the commit the binary was built from, else unknown
backup_dir	RECALL_BACKUP_DIR	off
backup_interval	RECALL_BACKUP_INTERVAL_MS	24h
backup_keep	RECALL_BACKUP_KEEP	7
rate_limit_window	RECALL_RATE_LIMIT_WINDOW_MS	60s
rate_limit_max	RECALL_RATE_LIMIT_MAX	60
trusted_ip_header	RECALL_TRUSTED_IP_HEADER	cf-connecting-ip, forced empty when tls is on
merge_enabled	RECALL_MERGE_ENABLED	on
merge_timeout	RECALL_MERGE_TIMEOUT_MS	45s
claude_bin	RECALL_CLAUDE_BIN	claude
claude_status_interval	RECALL_CLAUDE_STATUS_INTERVAL_MS	30m
ephemeral_device_ttl	RECALL_EPHEMERAL_DEVICE_TTL_HOURS	24h
public_url	RECALL_PUBLIC_URL	unset: passkey sign-in off
tls	RECALL_TLS_CERT/RECALL_TLS_KEY, or RECALL_TLS_ACME_DOMAINS/RECALL_TLS_ACME_EMAIL/RECALL_TLS_ACME_DIR/RECALL_TLS_ACME_STAGING	off
tls_max_connections	RECALL_TLS_MAX_CONNECTIONS	512

RECALL_TLS_REQUIRED is read but not stored: when it is true, a config with tls off refuses to start (ConfigError::TlsRequired).

Fields

addr: String

The socket to bind, assembled from host and port.

token: String

The single bearer token. There is no second one, by design.

db_path: String

The SQLite file. Opened, never created from a schema migration — it is the same file the Node server wrote. Kept in WAL mode, with its -wal and -shm files beside it, so it must be on a local filesystem (see Store::open).

git_commit: String

Reported by GET /health so a deploy can be confirmed from outside. A release binary knows its own commit, stamped at build time; the variable overrides it, for an image built from a checkout.

backup_dir: String

Where periodic database snapshots go. Empty disables backups.

backup_interval: Duration

How often to take one.

backup_keep: usize

How many to keep before deleting the oldest.

rate_limit_window: Duration

The window rate limiting counts requests over.

rate_limit_max: u32

How many requests one client may make in that window.

trusted_ip_header: String

The one request header whose value is taken as the client’s address, or empty to trust none and use the socket’s peer address.

Rate limiting keys off this, and rate limiting runs before auth precisely so a flood of invalid tokens is limited too — so a client that can choose its own value here can rotate it and get unlimited attempts at guessing the token.

That makes this a statement about the deployment, not a preference: it names the header the ingress sets, and it is only safe when nothing can reach this server except through that ingress. Exactly one header is read, so a value the client supplies under any other name is ignored.

Ingress	Set this to
Cloudflare Tunnel	cf-connecting-ip (the default)
Traefik, nginx, Caddy	x-real-ip
None — reached directly	empty

Deliberately not x-forwarded-for: a proxy appends to it, so the first entry is whatever the client sent. Reading it as one value is the classic way to make this setting useless.

merge_enabled: bool

Whether to attempt semantic merge at all. Off means last-write-wins.

merge_timeout: Duration

How long a merge may take before it is abandoned — and, like every other merge failure, degraded to last-write-wins.

claude_bin: String

The claude binary to shell out to. Never the Anthropic API.

claude_status_interval: Duration

How often to re-check that the binary is present and logged in.

ephemeral_device_ttl: Duration

How long an ephemeral device, one a cloud session enrolled with an ephemeral authkey, may go without a signed request before it is removed.

A day by default. A cloud session left open over lunch, a meeting or a night keeps its device; a day’s worth of finished sessions does not pile up in the device list; and the key a finished session left in its container stops working within a day of its last use.

public_url: String

The address people reach this server at, such as https://recall.example.com: an origin, with no path.

Passkeys are bound to a site, and the server cannot learn which one from a request: behind Traefik it sees plain HTTP, and a Host header is whatever the client sent. So the site is configured. The WebAuthn relying party id is its host and the origin a passkey must be used from is the whole of it. Empty leaves passkey sign-in on /admin off, and the page says so; nothing else depends on it.

tls: TlsMode

Whether this server terminates TLS itself. Off by default: the two existing deployments (deploy/docker-compose.yml, docker-compose.traefik.yml) put an ingress in front instead, and that stays the default. See TlsMode.

tls_max_connections: usize

How many connections the direct-TLS listener holds open at once, counting ones still in their TLS handshake. Ignored with TLS off, where the ingress in front owns this problem.

With no ingress, every idle or half-open socket an attacker opens costs this process a file descriptor and a task; this bound turns “exhaust the process’s descriptors” into “fill these slots until the timeouts in server/tls.rs close them”. A single owner’s machines need a handful; the default leaves generous room below the nofile limit docker-compose.direct.yml sets.

Implementations

impl Config

pub fn from_env() -> Result<Self, ConfigError>

Reads configuration from the real process environment.

pub fn from_lookup<F>(lookup: F) -> Result<Self, ConfigError>

where F: Fn(&str) -> Option<String>,

Reads configuration through a caller-supplied lookup, applying the same defaults the Node implementation used.

The lookup is injected rather than read from std::env inside so the clamping below is testable: set_var is process-global, and Rust runs tests in parallel threads, so an env-reading test races every other test in the binary.

An unparseable value falls back rather than failing the boot, matching the Node and Go implementations — a typo in one tunable should not be the reason a server won’t start.

Trait Implementations

impl Clone for Config

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Config

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Config

fn default() -> Self

Returns the “default value” for a type.